It was an enjoyable experience. But to me, it was more of a toy than a game. The objectives seemed ambiguous, and it was maybe a little rough around the edges.
I suppose the most traditionally game-like aspect was that score was based on how many of those red dots you'd killed/converted. That said, I wasn't that pleased that such a violent-feeling action would be rewarded in such an abstract work, but that is surely a matter of personal preference.
P.S.
A game called 'The Line' already exists. You could change the name of your game to avoid confusion, but it's probably not a big deal and is ultimately your choice.